Research Paper

 The Effect of Peak-End Theory on Perceptions of Marital Conflict

Dakota Elliott

Southern Utah University 

Abstract

Peak-end theory is the idea that experiences are evaluated based on how the experience was perceived at its most intense moment and how it ended, not based on the cumulative feelings averaged over the entire experience. An essential part of a meaningful life is having close interpersonal relationships such as those seen in marriages. Conflict in marriage is very common and can have detrimental effects on couples and children. Many studies have been conducted showing the utility of peak-end theory in different situations, however, none have directly studied its applicability to improving perceptions of marital conflict. This study aims to explore the effect of positive endings to conflicts on marital satisfaction, the number of conflicts experienced over time, perceptions of the severity of the conflict and perceptions of spouses. For three weeks, participants will read a letter written to them by their partner after each conflict, in an attempt to end the conflict positively. Participants will be randomly assigned into one of four experimental groups (Positive letter/together, neutral letter/together, positive letter/apart, neutral letter/apart). Results will be analyzed using two and three way ANOVAs. The literature suggests that participants in the positive ending/together group will have the most beneficial results. Should these hypotheses be supported, therapists and individuals could benefit from applying the peak-end theory to marital relationships.

The Effect of Peak-End Theory on Perceptions of Marital Conflict

This study integrates two topics, peak-end theory and marital conflict. Peak-end theory and its place in the field of positive psychology will be summarized first. This will be followed by a discussion on marital conflict, and then how the current study plans to integrate the two subjects.

            Positive psychology is a relatively new topic in the larger field of psychology. Although the concept was not new and previous research could have eluded to similar ideas, McNulty and Fincham (2012) suggest that the official subfield of positive psychology was created in 1998 by Martin Seligman. At this time, many psychologists had become disenchanted with the perceived dismal direction psychology was taking. Research and practice used psychology as a means of diagnosing or curing the faults and weaknesses of human beings in an attempt to understand and alleviate negative symptoms. This has been somewhat effective throughout the discipline’s existence, however, the American Psychological Association wondered if perhaps something was being overlooked. The intention behind the creation of positive psychology was to begin studying the strengths and qualities that humans innately possess and take advantage of them in order to increase subjective and universal well-being (McNulty & Fincham, 2012).

            Although McNulty and others have criticized positive psychologists for oversimplifying the study of human behavior as either positive or negative (McNulty & Fincham, 2012), there have been many recent studies offering support for the sub-field's potential for good. Park and Chen (2016) argue that positive psychology can be used to improve the lives of individuals with mental illnesses. People who live with these illnesses, disabilities, and the effects of trauma, who may have no reason to believe that their negative symptoms will ever go away, may benefit from cultivating hope, pleasure, courage and other characteristics that are the purview of positive psychology. Park and Chen posit that these traits can be taught or encouraged through evidence-based interventions given by practitioners and mental health professionals (Park & Chen, 2016).

            The utility of positive psychology interventions has also been discussed by Gander, Proyer and Ruch (2016), who suggest that these are effective because each individual can select from one of the many empirically studied interventions to find one that fits their personal needs. One of the most common interventions used is based off of Martin Seligman’s Authentic Happiness Theory. It is designed to help people have meaningful, pleasant, and engaged lives while also developing positive interpersonal relationships and significant accomplishments. Through developing strengths and skills in these five areas, people may see improvements in their overall wellbeing and happiness for up to six months (Proyer et al., 2016).

            Another domain that is studied in positive psychology is the effect of positive emotions on the body and cognition. Fredrickson (2001) described how negative emotions cause individuals to experience a narrowing of attention and specific physical reactions attributed to the body’s “fight or flight” response. While studying emotional responses, she discovered that very little was known about the physical effects of positive emotions on the body. After creating an experiment that caused participants to feel positive emotions such as joy and contentment, she discovered that individuals became more active, were able to think more creatively, solve problems more efficiently, and many experienced an increase in physical health because they could successfully cope with previously experienced negative emotions (Fredrickson, 2001).

Peak-End Theory

            Although emotions have been shown to affect well-being in significant ways, many researchers have found it difficult to accurately record human emotions because of a concept called remembered utility. Another common term for remembered utility is the Peak-End Theory, which was described by Kahneman, Fredrickson, Schreiber and Redelmeier in 1993. Peak-end theory states that when the human brain remembers or evaluates an experience, it does not do so cumulatively. The most important parts of an experience are the emotions felt at the most intense point (the peak), and at the ending of the experience. Through a series of experiments, the peak-end theory held up even when it defied basic logic (Kahneman et al. 1993).

            For example, in one study they conducted participants were asked to place their hands in very cold water for 60 seconds and constantly rate how much discomfort they were experiencing. They then were asked to place their hands in the very cold water for another 60 seconds. During this round, the participants unknowingly kept their hands in the water for an additional 30 seconds while the temperature of the water was raised slightly. The order of each trial was randomly selected for each participant to avoid confounds relating to the order of the trials. After these two trials were completed, they were required to pick one of the trials to repeat. Most participants picked the trial that was longer but had the slightly better ending. Kahneman et al. argued that logically, participants should have picked the shorter trial because it would have produced less discomfort overall. However, because the longer trial had a somewhat better ending, the participants remembered it more favorably than the shorter trial (Kahneman et al., 1993).

Kahneman and Redelmeier (1993) (cited in Kahneman, Fredrickson, Schreiber, and Redelmeier, 1993) also found this phenomenon to be true with patients who underwent a painful medical procedure. Participants whose experience had a longer but slightly less painful ending, rated the experience better on average than those who had shorter procedures that ended with constant levels of discomfort.

Additional studies have been conducted to test the generalizability of peak-end theory to other areas of interest such as learning. Finn (2010), gave participants a very difficult set of Spanish-English pairs to memorize and recall. The researcher’s design was very similar to the original study by Kahneman in that there were two trials, one with a set of only 30 difficult words, and a second set with 30 difficult words plus an additional 15 words of medium difficulty. Participants were asked to report which set they would like to complete for a third trial. A significant number of participants reported that they would choose the larger set that ended with the 15 medium-difficulty words (Finn, 2010).

Hoogerheide and Paas (2012) also attempted to show that Peak-End Theory is a useful framework for helping students learn more effectively. They criticized Finn for choosing an experimental design that was too unrealistic to be applied in a classroom. Hoogerheide and Paas changed their design and focused on supporting the idea that student’s evaluations of a difficult studying session can be manipulated in order to increase their likelihood of choosing to engage in a difficult educational task again. In their study, they asked students to memorize Dutch-English word pairs and take a test on them. One of the trials had additional words to memorize, but which were easier to learn. A significant number of participants chose to receive the longer list of words, and this effect lasted for up to one week after the experiment ended (Hoogerheide & Paas, 2012).

Kahneman et al. (1993), Finn (2010), Hoogerheide and Paas (2012) all support the peak-end theory. Although the domains of learning and discomfort are the only topics that have been empirically studied, the authors suggest that there are many more possibilities for the application of this theory. They suggest the need for additional investigations to be conducted on peak-end theory.

Marital Conflict

Meaningful relationships play an important role in having a happy and satisfactory life. Reis and Gable, (2003) discussed the idea that the people who experience the most well being in life are often the ones with stable and successful interpersonal relationships. Most people desire to have positive interactions with others and develop deep connections with people (Reis & Gable, 2003). Maslow, in his revolutionary essay on human’s hierarchy of needs suggested that feelings of love and belonging come only after physiological and safety needs are met and is a requirement for self-actualization (1943). One of the most common ways for people to attain love and cultivate meaningful relationships is through the institution of marriage.

Although marriage can be one means to achieve extreme happiness and fulfillment in life, it also has the potential for causing distress and misery. The reason that misery is so prominent in relationships is that conflict is often present.  Agreeing to be in a close relationship, such as marriage, puts individuals in a vulnerable position where conflicts and disputes may become destructive and their most private emotions may be exposed. Reis and Gable described how common it is for relationships to be the cause of health problems, stress, and depression if unresolved. Indeed, many other academics who have investigated the effects of marital conflict on health and life satisfaction.

Fincham (2003), compiled a list of some of the known negative consequences of marital conflict. Some studies have found that marital conflict is related to increased amounts of substance abuse and addictions, increased rates of diseases and life-threatening health problems, higher chances of being a victim or perpetrator of violence, and a decreased ability to be successful in other important relationships like parenting.

When a couple’s ability to parent decreases because of couple distress, children can be negatively affected. Many studies have shown the detrimental effect that witnessing conflict has on children’s ability to function, perform well in school, and have successful future relationships. Marital conflict also affects the family unit as a whole; parents who fight are more likely to fight with their children and have children who fight with each other (Fincham, 2003).

Logically, one would think that the most effective way to ameliorate the negative effects of marital conflict would to be to eliminate marital conflict altogether. However, researchers such as Gottman and Levenson (2000) suggest that this is unrealistic and would not totally solve the problem. No intimate relationship is free of conflict; it is a result of imperfect humans living and experiencing the world together. Gottman and Levenson suggest that marital conflict can actually be beneficial, but only if it is resolved and managed properly. They proposed that there are different conflict management styles that may contribute to the success and level of benefit that couples receive from conflict.

These conflict management styles (i.e. avoidant, validating, volatile and hostile), were defined more completely by Busby and Holman (2009). The avoidant style is evident when a conflict arises and one or both individuals shy away from resolution and hope that the problem will go away on its own. The validating style occurs when a dispute is handled in a civil and direct manner, where both sides are respected and valued equally. Individuals who use the volatile style are more likely to use intense emotions and heated debates to solve problems. Busby and Holman argued that the previous three styles are not problematic on their own and each one has its merits. The literature suggests that the only universally problematic style is that of hostility. This occurs when individuals in a marriage try to purposefully hurt or offend each other and have no respect or positive regard for their partner. Each individual maintains their own style of resolving conflict and the most successful couples have matching styles.

When one considers the best way to resolve a conflict, the validating style may seem superior to all other styles and be the only option that seems legitimate. However, styles that may seem contrary to common sense, such as the avoidant style do present some benefits to couples. The avoidant style offers the opportunity to successfully resolve a conflict without the couple being together or discussing the problem.

Busby and Holman also posited that the avoidant style, although not harmful in and of itself, may often be confused with what Gottman termed “stonewalling,” which is very destructive in a relationship. Stonewalling is one of the “four horsemen of the apocalypse,” or the four conflict behaviors that have been shown to accurately predict relationship turmoil and future divorce. Although an avoidant style of conflict management is similar to stonewalling in that the partners don’t communicate with each other, stonewalling is characterized by one or both partners becoming so upset during a dispute that they refuse to speak, out of fear that they will lash out (Busby & Holman, 2009). It is important for couples to make this distinction when trying to understand the ways they resolve conflict. If they are stonewalling instead of simply avoiding, change may be necessary to avoid relationship termination.

Similar to the idea that conflict resolution styles should “match,” Fincham (2003) described the impact that negative and positive reciprocity have on conflicts. Negative reciprocity, or responding negatively to your partner’s negative behavior, creates more conflict. If the couple can find a way to respond more positively to their partner’s negative behavior, they are more likely to find solutions and produce harmony after tense emotions are felt. For many distressed couples, it is very difficult to have positive reciprocity, thus they default to negative reciprocity and conflicts spiral out of control and can cause serious damage to the relationship.

Gottman and Levenson (2000), suggests that couples who truly want to resolve conflict, or more accurately, prevent it, should adopt the practice of a “soft start-up.” A soft start-up means that partners should be polite, clear, and calm while attempting to bring up a difficulty that could potentially result in conflict. By creating a respectful environment in the beginning, the problem is less likely to escalate into a conflict at all and partners will be able to avoid the problems of negative reciprocity.

They also suggest that positive interactions and emotions are necessary to a marriage’s success. When couples fall below a ratio of one positive interaction to one negative interaction, their chance of divorce increases and can be accurately predicted years in advance. The optimal ratio of interactions is five positive for every one negative (Gottman & Levenson, 2000).

Fredrickson (2001), also supports the importance of positive emotions and interactions in relationships. In her study, she found that positive emotions were able to “undo” the effects of a negative experience and even eradicate negative emotions. By creating positive emotions in a conflict situation, positive reciprocity would result and could be an effective tool in resolving the conflict.  Hawkins, Carrere, and Gottman (2002) described a phenomenon similar to this called sentiment override, where a person who views their relationship as positive is more likely to dismiss or interpret their partner’s negative behavior as less severe. It would be beneficial for couples to have strong marital connections in order for them to view their interactions in a more positive light.

Peak End Theory and Interpersonal Relationships

Although the connection has not been formally made between marital conflict and peak-end theory, some studies have discussed the relationship between positive endings and interpersonal relationships.

Fraser (2013), drew a connection between peak-end theory and relationships in business. He stated that businesses can use this theory to their advantage and create a positive image for their company. When an employee leaves the company, whether because of being fired or for personal reasons, businesses should make the experience amicable and meaningful. The thing that an employee will remember the most about a company is probably what they experienced at the very end. Thus, if a business wants the previous employee to write good reviews or continue to promote the company instead of talk badly about it, it is in their best interest to make it a good experience.

In another study, researchers studied the effect of ending a conflict positively on children. Davies, Myers, and Cummings (1996), showed children and adolescents vignettes of a couple arguing about a topic, then going behind a closed door, followed by the couple coming out either arguing about an unrelated topic or pleasantly conversing about an unrelated topic. The researchers then asked the children to imagine the couple were their own parents and how viewing this interchange would make them feel. The children who viewed the couple pleasantly conversing after reemerging from the closed door, had more positive responses and lower levels of distress as compared to children who witnessed the couple arguing after reemerging.

            These two connections support the idea of peak-end theory being used in the interpersonal realm, however, no known research has directly studied the effect of peak-end theory on perceptions of marital conflict. The present study will seek to understand this relationship. The purpose of the study is not to find a new way to resolve conflict, but to determine if ending marital conflicts on a positive note can be advantageous in making a marital dispute seem more positive.

            If ending a marital conflict in a positive way can alter a person’s perception of the conflict, it will increase the positive to negative interaction ratio talked about by Gottman, eliminate negative emotions and their effects as discussed by Fredrickson, and create sentiment override that will help couples overlook the negative behaviors of their spouses. Because marriage and close interpersonal relationships are essential to a happy life, it is important for research to discuss the ways that are most effective in decreasing the negative aspects of marital relationships. It is also important for couples to have strong relationships and to avoid conflict in order to help their children succeed in life.

            The researchers will investigate how perceptions of marital conflict are affected by peak-end theory by putting participants into one of four experimental groups. Participants will experience a positive ending by reading a positive letter written by their spouse, at the end of each conflict for three weeks. Some participants will be in the control group and will read neutral, but personal letters from their spouse at then end of each conflict. Participants will also be split into two social environment groups; reading letters together or apart. According to Busby and Holman (2009) being apart does not significantly alter a couple’s ability to resolve a conflict. Thus, the present study seeks to understand if being apart or together will also alter perceptions of the conflict.

This study aims to understand if positive endings to marital conflicts will effect a person’s perception of the severity of a conflict, their perceptions of their partner, their marital satisfaction, and the number of conflicts they experience. The experiment will investigate four main hypotheses. 1. Do couples who read a positive letter together after a conflict rate the conflict as less severe in comparison to groups who read positive letters apart, neutral letters together, and neutral letters apart? 2. Do couples who read a positive letter together at the end of a marital conflict rate their spouses more favorable than all other groups? 3. Do couples who read a positive letter together at the end of a conflict show an increase of marital satisfaction as compared to all other groups? 4. Do couples who read positive letters together after a conflict experience fewer conflicts over time in comparison to all other groups?

Method

Participants

Married couples will be recruited from a small community and university in the southwestern United States. Their ages will range from 18-80 and there will be an even number of men and women due to the fact that they will be recruited as a couple. Due to the ethnic and cultural nature of the community where the research is being conducted, the sample will most likely consist of a majority of white, college-aged, Christian individuals. Couples who have been married for less than six months, have attended therapy in the past two years, or who have been victims or perpetrators of domestic violence will not be included. Research has shown that couples who are extremely distressed may react poorly to positive interventions (McNulty & Fincham, 2012). Participants who are recruited from the university will receive up to 4 credits to go towards a research participation for a psychology 1010 class. All participants will be eligible to win one of four date night packages with a value starting at $100. These date night packages may include a night stay at a hotel, gift cards to restaurants, or tickets to other activities.

Materials

Pre-Study Screening Questions: Prior to participating, each person will be required to indicate whether they can answer affirmatively to any of the questions on this four item self report measure. If a participant can answer yes to at least one of the questions, they will not be allowed to continue participation. Although it is required to report if they could answer affirmatively, they do not have to designate which of the questions they are referring to (see Appendix A).

Basic Demographic Survey: This is an eight item questionnaire asking demographic questions such as age, race, religion and length of marriage (see Appendix B).

Marital Satisfaction Inventory-Revised. This is a 150 item, true/false questionnaire asking about an individuals satisfaction within their marital relationship. It contains 13 sections: inconsistency, conventionalization, global distress, affective communication, problem-solving communication, aggression, time together, disagreement about finances, sexual dissatisfaction, role orientation, family history of distress, dissatisfaction with children and conflict over rearing children. Sample questions from the role orientation section include: "the man should be the head of the family" and "the most important thing for a woman is to be a good wife." The test-retest reliability has an average coefficient of .79 with Cronbach’s alpha maintaining an average coefficient of .82. Convergent and discriminant validity are also well established (Means-Christensen, Snyder & Negy, 2003).

Scripts Prompts: Each participant will be asked to write eight short letter to their spouse based off of eight prompts. Participants will be given set 1 if they are in the positive ending script group, and set 2 if they are in the neutral ending script group (see Appendix C).

Mini-Questionnaire: This is a four item questionnaire asking participants about their perceptions of the previous conflict they engaged in. Questions include how participants would rate the severity of the conflict on a 1-7 lichert scale, their perceptions of their partner’s agreeableness on a 1-7 lichert scale, what the conflict was about, and how long the conflict lasted (see Appendix D).

Procedure

Once individuals contact the researchers, they will be emailed the pre-study screening questions. They will be informed that if they can answer yes to any of the pre-study screening questions, they will not be allowed to participate. They should not indicate which of the questions they can answer yes to. This way, those who do not qualify may be filtered out without any confidential information being divulged. If they qualify, they will be invited to set up a time to meet with the researchers at the university to receive the instructions for the study.

During this initial meeting, participants will be given the informed consent and be randomly assigned to one of four experimental groups: (Positive Ending/Together, Positive Ending/Apart, Neutral Ending/Together, Neutral Ending/Apart). They will then be asked to fill out the basic demographics survey, then take the Marital Satisfaction Inventory-Revised.  Participants will be asked to write 8 letters to their partner based off the set of prompts that has been assigned to their experimental group. They will be instructed not to read them or share them with their partner until there is a significant marital conflict. They will write these letters in a bound notebook that includes multiple, blank mini-questionnaires. Once they have completed the letters based off of the prompts, the participants will be instructed on what they are to do for the next three weeks (these instructions will vary based on the experimental groups they are assigned to). Those in the together groups will read their scripts in each others’ presence, the apart group will read the scripts in different rooms. These instructions are as follows: "Every time you have a significant marital conflict (defined as any situation in which one or both partners in the marriage is experiencing emotional distress because of a disagreement, misunderstanding or an instance of poor communication between spouses) in your home, you will read one of the 8 letters that your partner has written to you immediately after the conflict ends. You may choose the letter that you read at random. You do not have to read the letter aloud. After reading the letter, fill out the mini-questionnaire. If you run out of letters to read (having more than 8 conflicts during the 3-week period,) you may start over and re-read the letters." Conflicts that occur outside of the home will not be included in this study, as participants may not have access to the materials needed or may not be able to be physically separated. The literature also suggests that a majority of significant marital conflicts occur in the home.

The researchers will then role-play the instructions, so as to be clear of what behavior is needed, then the researchers will ask for questions. Once all questions have been answered, the spouses will exchange notebooks so that they have the letters that their partner has written to them. The researchers will set up a time for the couple to return in 3 weeks. The participants will then be dismissed for the 3-week period.

At the 3-week follow-up, participants will turn in their journals containing the mini-questionnaires (the letters included in the journals will be removed to maintain privacy and confidentiality). The participants will then be asked to take the Marital Satisfaction Inventory-Revised again. After completing the inventory, the participants will be debriefed on the true nature of the experiment, what the hypotheses were, and which experimental group they were in. (Although the deception used in this study is minor and is merely withholding information, it is imperative that the participants do not know the hypotheses of the researchers in order to maintain validity and avoid biases/confounds). They will be given the opportunity to be contacted once data has been analyzed to know if significant results were found in relation to if any of the groups showed significant benefits to marital satisfaction because of the intervention. They will also be given the information on when the prizes will be given out.

Statistical Analyses

To investigate the effect of ending letter type and social environment on perceived conflict severity, a 2-Way independent ANOVA was conducted. It is anticipated that those in the positive ending group who read their letters together will have significantly lower severity scores on the mini-questionnaires than participants in all other groups. The literature suggests that when positive emotions are created, it can eliminate the negative effects of a conflict (Fredrickson, 2003).

To examine the effect of ending letter type and social environment on perceived agreeableness of the partner, a 2-Way independent ANOVA will be conducted. Participants in the positive ending group who read their letters together are expected to have significantly higher scores on the partner agreeableness measure of the mini-questionnaire than all other groups. Hawkins et al. (2002) suggest that when an individual perceives their marriage more positively, they are more likely to forgive their partner’s negative behavior. It may also be possible that a positive experience with a partner may result in forgiveness of negative behavior as well.

To investigate the effect of ending letter type and social environment on the number of conflicts over time, a 3-Way mixed ANOVA will be conducted. It is anticipated that those in the positive ending group who read their letters together will have significantly fewer marital conflicts over the three-week intervention than those in all other groups. If there are positive interactions occurring and the end of a conflict, positive reciprocation might become a more prevalent pattern (Fincham, 2003), thus resulting in a decreased number of conflicts.

To examine the effect of ending letter type and social environment on marital satisfaction, a 2-Way independent ANOVA will be conducted. Participants in the positive ending group who read their letters together are expected to have significantly higher change of score on the marital satisfaction inventory from the first time of taking it to the second time, in comparison to participants in all other groups. According to Gottman and Levenson (2000), by increasing the ratio of positive to negative interactions, a marriage will fare better and be less susceptible to divorce.

References

Busby, D. M., & Holman, T. B. (2009). Perceived match or mismatch on the Gottman conflict styles: Associations with relationship outcome variables. Family Process. 48(4), 531-545.

Davies, P. T., Myers, R. L. & Cummings, M. E. (1996). Responses of children and adolescents to marital conflict scenarios as a function of the emotionality of conflict endings. Merrill-Palmer Quarterly, 42(1), 1-21.

Fincham, F. D. (2003). Marital conflict: Correlates, structure and context. Current Directions in Psychological Science, 12(1), 23-27. DOI: 10.1111/1467-8721.01215

Finn, B. (2010). Ending on a high note: Adding a better end to effortful study. Journal of Experimental Psychology: Learning, Memory and Cognition. 36(6), 1548-1553. DOI: 10.1037/a0020605.

Fraser, A. (2013). Peak-end theory. Retrieved from www.dradamfraser.com.

Frederickson, B. L. (2001). The role of positive emotions in positive psychology: The broaden-and-build theory of positive emotions. American Psychologist, 56(3), 218-226. DOI: 10.1037//0003-066X.56.3.218

Gander, F., Proyer, R. T., & Ruch, W. (2016) Positive psychology interventions addressing pleasure, engagement, meaning, positive relationships, and accomplishement increase well-being and ameliorate depressive symptoms: A randomized, placebo-controlled online study. Frontiers in Psychology. 7(Article 686), 1-12. DOI: 10.3389/fpsyg.2016.00686.

Gottman, J. M. & Levenson, R. W. (2000). The timing of divorce: Predicting when a couple will divorce over a 14-year period. Journal of Marriage and the Family, 62, 737-745.

Hawkins, M. W., Carrere, S., & Gottman, J. M. (2002). Marital sentiment override: Does it influence couples’ perceptions? Journal of Marriage and Family. 64(1), 193-201. DOI: 10.1111/j.17413737.2002.00193.x.

Hoogerheide, V. & Paas, F. (2012) Remembered utility of unpleasant and pleasant learning experiences: Is all well that ends well? Applied Cognitive Psychology, 26, 887-894. DOI: 10.1002/acp.2890

Kahneman, D., Fredrickson, B.L., Schrieber, C.A., & Redelmeier, D. A. (1993). When more pain is preferred to less: Adding a better end. Psychological Science, 4(6), 401-405. Retrieved from: http://brainimaging.waisman.wisc.edu/~perlman/0903-EmoPaper/KahnemanFredricksonScreiberRedelmeier_1993_WhenMorePainIsPreferredToLess.pdf

Maslow, A. (1943). A theory of human motivation. Psychological Review, 50, 370-396.

McNulty, J. K., & Fincham, F. D. (2012). Beyond positive psychology? Toward a contextual view of psychological processes and well-being. American Psychologist. 67(2), 101-110. DOI: 10.1037/a0024572.

Means-Christensen, A. J., Snyder, D. K., & Negy, C. (2003). Assessing nontraditional couples: Validity of the marital satisfaction inventory-revised with gay, lesbian, and cohabiting heterosexual couples. Journal of Marital and Family Therapy. 29(1), 69-83.

Park, J., Chen, R. K. (2016). Positive psychology and hope as means to recovery from mental illness. Journal of Applied Rehabilitation counseling. 47(2), 34-42. ISSN: 0047-2220

Reis, H.T., & Gable, S. L. (2003). Toward a positive psychology of relationships. In C. L. M. Keyes & J. Haidt (Eds.), Flourishing: Positive psychology and the life well-lived (pp. 129-152). Washington DC: American Psychological Association.